Coaxial cable connector



Mafch 19, 1957 H. J. ARBEITER 2,786,095

COAXIAL CABLE CONNECTOR Filed Sept. 12', 1952 INVENTOR Henry J Arbe/fer 7 A/forney United States Patent COAXIAL CABLE CONNECTGR Henry J. Arbeiter, Philadelphia, Pa., assignor, by mesne assignments, to Jerrold Electronics Corporation, a corporation of Delaware Application September 12, 1*)52, Serial No. 369,243

Claims. (Cl. 17488) This invention relates to electric transmission lines and particularly relates to a connector for interconnecting two portions of a coaxial electric transmission line.

Coaxial transmission lines are widely used in high frequency systems where it is important to keep the wave characteristics substantially constant. If the connector in the line is of a size that varies greatly from the remainder of the line it will aiiect the wave shape and impair the signal. It is, therefore, necessary to provide a connector that has a diameter which does not vary greatly from the diameter of the cable itself.

Heretofore, such connectors, in order to be of a diameter approximating the cables diameter, have been of the push type. However, such a connector was easily disconnected by undue or accidental jarring.

It is, therefore, an object of my invention to provide a rigid coupling for a coaxial transmission line.

Another object of my invention is to provide a mechanical connector wherein the connector is substantially of the same diameter as the transmission line.

Another object of my invention is to provide a connecting means between the connector and the coaxial cable which is simple but firm and strong in use.

Another object of my invention-is to provide a mechanical means to secure a permanent connection between the connector and the coaxial cable.

Other objects of my invention are to provide an improved device of the character described, that is easily and economically produced, which is sturdy in construction, and which is highly eflicient in operation.

With the above and related objects in view, my invention consists in the details of construction and combination of parts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawing in which:

Fig. 1 is a view showing of a clamping collar being clamped, by a special tool, into position to hold a connector to a coaxial cable.

Fig. 2 is a perspective view showing the clamping collar clamped in position.

Fig. 3' is a perspective view of the clamping collar be fore being clamped in position.

Fig. 4 is a fragmentary sectional view of the coupling portion of the connector assembly.

Fig. 5 is a perspective view of the connector assembly.

Fig. 6 is a side elevational view of the clamping tool.

Fig. 7 is a sectional view of the connector assembly.

Referring now in detail to the drawing wherein similar reference characters refer to similar parts, I show a coupling member generally designated as A which is connected to a tubular member B which is adapted to be connected to a coaxial cable by means of a clamping collar C. The collar C is adapted to be crimped into holding posi tion by a tool D.

The members A and B combine to form the connector assembly, the member A comprising an enlarged cylindrical portion 10 which is provided with an internally threaded bore 12 to receive the coupling unit of the other part of the transmission line. A shoulder 14 is formed in the bore and on this shoulder is adapted to lie the flange 16, which is provided on the end of the tubular portion 15 of the member B surrounding its bore 17. The outer periphery of the member A is tapered inwardly as at 18 and then recessed as at 20 to form a flange 22. The flange 22 is adapted to abut against the top surface 24A of a flange 7.4 formed on the member B so as to limit relative movement between the members A and B. A smooth bore 22A is provided in member A to receive portion 15 of member B. Relative movement is limited in one direction by shoulder 14 and flange 16 and in the opposite direction by flanges 22 and 24. The tubular portion 15 is provided with a tapered portion 25 forming a shoulder 25A.

The flange 24 is provided with a recess 26 and this recess is adapted to receive the uninsulated ends of the braided conductor 28 which forms the outer conducting portion of the coaxial cable. These ends of the braided conductor are indicated in Fig. 7. The inner conductor 30 of the coaxial cable plus its insulation 32 extends through the bore 17 of the member B. The insulation 32 is stripped away sufliciently to allow the inner conductor 30 to extend into the threaded bore 12 of the member A.

In applying the connector of this invention to a coaxial transmission line, an endof a coaxial cable 34 is prepared for attachment to the connector by stripping away a small endportion of the outer insulation surrounding the outer layer of braided conducting wire 28. The member B of the connector is then applied to this stripped end of the cable by inserting the end of the member B between the outer conductor 28 and the insulation 32. The inner conductor 30 and its insulation 32 is thereby received in the bore 17 of the member )3 while the end of the member B is received within the coaxial cable. In effect there is a telescoping action between the member B and the coaxial cable 34. Since the end portion of the outer conductor 28 is stripped, its strands are forced into the recess 26 of the flange 24. Preferably only a minimum of insulation should be stripped away so that some insulation as well as the bare conduction wire can be forced into the recess 26 in order to provide a strong frictional grip between. the parts. The outer part of the cable 34 has a portion which is stretched over shoulder 25A and frictionally held thereby.

When the cable 34 and the member B have been telescopically fitted together in the manner above described, a clamping collar C is used to clamp the cable and the connector. together. This collar C is passed up on the cable until it lies. adjacent the flange 24. In thisposition it overlies that portion of the cable which telescopically holds the lower portion of the member B within it. The collar C is then crimped by a special tool D so that there are formed two oppositely formed flanges or p nched portions 36. Only one such pinched portion 36 is shown in Fig. 2. Since the crimped. part of the collar is evenly divided between the two portions 36, the total diameter of the collar remains substantially the same as the diameter of the connector and not much greater than the diameter of the cable. Furthermore, the clamping action of the collar is evenly distributed around the periphery of the cable.

The tool D is especially constructed so that it crimps the collar C into the exact configuration desired. The tool comprises two arms 40 and 42 pivoted at 44 and aving complementary recesses 46 and 48 which combine to form a circular opening 49 which has a diameter substantially equal to that of the cable and has oppositely disposed slots 50 and 52 extending therefrom. The tool D is applied over the collar C with the collar held between the two recesses 46 and 48. When the arms 40 and 42 3 are pressed together as in Fig. 1, the jaws formed by the recesses press the collar into its predetermined configuration determined by the circular opening 50 and the slots 50 and S2. The slots 50 and 52 form the pinched portions 36 which consist of the extra material squeezed out of the collar by the recessed jaws.

After the connector has been attached to the coaxial cable 34, in the above manner, it is ready to be threadedly coupled to the other section of the transmission line.

Although my invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to be determined as claimed.

I claim as my invention:

1. A mechanical coaxial cable connector comprising (a) an outer telescoping cylindrical electrically conducting member having an internally threaded bore for holding a connecting coaxial cable fitting, and having an internal shoulder formed in said bore near its rear end, (b) an inner telescoping cylindrical electrically conducting member having an inner bore of a diameter just sufiicient to hold the inner conductor of a coaxial cable and its insulation, said inner member having a flange formed on its front end to abut against the internal shoulder on the outer member to limit movement of the members in one direction, and a second flange formed upon it rearward of the end of the outer member to limit relative movement of the members in the other direction, the second flange being provided with a recess on its rear face, the inner conducting member extending rearwardly from the second flange a suflicient distance to provide a bearing surface, (c) a coaxial cable partially stripped at its forward end, fitting into and about the inner member, with a portion of uninsulated central conductor protruding forward of the member, insulated central conductor fitting the bore of the member, outer conductor and its insulation covering the rear end and bearing surface of the member, the loose ends of the outer conductor being forced into the recess on the rear face of the second flange of the member, (d) an enlargement at the rear end of the cylinder and (e) a collar crirnped about the bearing surface, outer conductor and insulation rearwardly of the second flange whereby firm direct electrical contact is made between the outer conductor and the bearing surface, and firm mechanical contact is made between the outer conductor with its insulation and the bearing surface.

2. A coaxial cable terminal comprising (1) a coaxial cable having a central conductor, inner insulation, outer conductor and outer insulation, (2) a unitary hollow elongated cylinder having an internal bore of a diameter just suflicient to hold the inner conductor and inner insulation of the coaxial cable, means on the forward end of the cylinder to engage in restraint a coupling element for engagement with a second coaxial cable, the cylinder extending rearwardly for a sufficient distance to provide a substantially cylindrical bearing surface against which the outer conductor and outer insulation can be clamped to ground the outer braid on the fitting and provide a firm mechanical connection, the coaxial cable being stripped at its forward end to fit into and about the cylinder, with a portion of uninsulated central conductor protruding forward of the cylinder, said insulated central conductor filling the bore, and said outer conductor and said outer insulation, covering the cylindrical bearing surface, with said outer insulation in direct contact with said outer conductor and (3) mechanical means mounted on and bearing against the outer insulation and acting in a plane normal to the axis of the cable for both grounding the outer conductor directly, and clamping the outer conductor and outer insulation, against the cylindrical bearing surface.

3. A coaxial cable terminal comprising (1) a coaxial cable having a central conductor, inner insulation, outer conductor and outer insulation (2) a unitary hollow elongated cylinder having an internal bore of a diameter just sufficient to hold the inner conductor and the inner insulation of the coaxial cable, means on the forward end of the cylinder to engage in restraint a coupling element for engagement with a second coaxial cable, a flange formed on the outside of the cylinder to mark the maximum forward position of the outer conductor and outer insulation, the cylinder extending rearwardly of the flange for a suflicient distance to provide a substantially cylindrical bearing surface against which the outer conductor and outer insulation can be clamped to ground the outer braid on the fitting and provide a firm mechanical connector, the coaxial cable being stripped at its forward end to fit into and about the cylinder, with a portion of uninsulated central conductor protruding forward of the cylinder, said insulated central conductor filling the bore, and said outer conductor and outer insulation, covering the cylindrical bearing surface, with said outer insulation in direct contact with said outer conductor and (3) mechanical means mounted on and bearing against the outer insulation and acting in a plane normal to the axis of the cable for both grounding the outer conductor directly, and clamping the outer conductor and outer insulation against the cylindrical bearing surface.

4. The terminal of claim 2, in which the rear end of the cylinder is of greater diameter than the cylindrical bearing surface, and the locking means comprises a crirnped collar clamping the outer conductor and insulation in place against the cylindrical bearing surface.

5. The terminal of claim 3, in which the rearward edge of the flange is constructed with a recess therein to hide the loose ends of the outer conductor.

References Cited in the file of this patent UNITED STATES PATENTS 2,148,392 Ransone Feb. 21, 1939 2,156,772 Seeley May 2, 1939 2,328,747 Schweidler Sept. 7, 1943 2,425,834 Salisbury Aug. 19, 1947 2,435,562 Swengel Feb. 3, 1948 2,435,989 Webster Feb. 17, 1948 2,536,003 Dupre Dec. 26, 1950 2,577,049 Uline Dec. 4, 1951 2,583,067 Strunk Ian. 22, 1952 2,640,095 Lewis et al May 26, 1953 

